Back in the 70s, PRT considered the future of transit

CabinTaxi system slated for Detroit and Hamburg

Technology rolled into Raytheon 1996-1999, later disassociated into Taxi2000 SkyWeb Express

Boeing also working on people movers, deployed only operational system in 1975; software and maintenance handed over to local staff in 2003

ULTra system in UK winning near-term contracts for parking-lot people movers

Major failing in economics: very expensive infrastructure per mile